The issue occurs if you are trying to download a content that is not available in the marketplace server anymore.
The content you are trying to download owncloud-ova-10-0-9-0 is no longer available in marketplace server. There is a newer version available owncloud-ova-10-0-10-2 (link : VMware Solution Exchange ).
To not see the older not supported contents in vRSLCM marketplace, set the full sync property in lcm.properties( path : /opt/vmware/vlcm/config/lcm.properties) file as true and trigger a marketplace sync refresh.
Once the sync request is completed, you would observe that the older not supported versions are removed from vRSLCM as well.
You can always download the newer version available in marketplace.
PS : Set the fullSync to false once the process is completed. This will ensure syncs are done in delta mode and improves the performance.